Finasteride is a medication commonly prescribed to address two distinct conditions: male pattern hair loss (androgenetic alopecia) and benign prostatic hyperplasia (BPH), an enlarged prostate. For hair loss, it is typically used at a lower dose (1 milligram daily), while a higher dose (5 milligrams) is common for BPH. A frequent concern for individuals considering or using this medication is its potential effect on male fertility. This article explores the scientific understanding of finasteride’s relationship with male reproductive health and fertility.
Understanding Finasteride’s Action
Finasteride functions as a 5-alpha reductase inhibitor. It blocks the enzyme 5-alpha reductase, particularly its Type II isoform. This enzyme is present in tissues like the prostate, skin, and liver, where it converts testosterone into dihydrotestosterone (DHT).
By inhibiting this conversion, finasteride significantly reduces DHT levels in the body. This reduction helps to slow hair loss and can reduce prostate size, alleviating symptoms of BPH. DHT plays a role in male pattern baldness by shrinking hair follicles and contributes to prostate growth. This mechanism impacts the hormonal environment, which is linked to male reproductive processes.
Finasteride and Male Fertility
While finasteride primarily targets DHT for hair loss and prostate enlargement, its influence on male sex hormones can affect fertility in some men. Studies indicate finasteride can lead to changes in certain semen parameters, including a reduction in semen volume and sperm count. However, these effects are not universally observed and are generally reversible upon discontinuation.
The potential impact on fertility stems from DHT’s role in the male reproductive system. Although finasteride does not directly affect testosterone levels, altering the balance of these hormones might influence spermatogenesis, or sperm production. Some research suggests that while sperm count and semen volume may decrease, sperm motility and morphology are not consistently affected. However, some reports have associated finasteride with reduced sperm motility.
Research findings indicate that the effects on semen quality can vary among individuals, with some men experiencing more noticeable changes, particularly those with pre-existing fertility challenges. For instance, one study found that even low doses of finasteride (around 1 milligram per day) could reduce sperm counts in some men. These changes are reversible; for men who experienced reduced sperm counts, discontinuation of finasteride led to significant improvements, with one study reporting an average 11.6-fold increase in sperm counts. These improvements often manifest within a few months, typically within six months of stopping the drug. Finasteride is not known to cause permanent infertility.
Addressing Fertility Concerns
For individuals taking finasteride or considering its use who have fertility concerns, open communication with a healthcare provider is important. A doctor can offer personalized guidance based on an individual’s health profile and family planning goals, especially if trying to conceive or facing fertility challenges.
A healthcare provider might recommend a fertility evaluation, including a semen analysis, to assess sperm parameters like count, motility, and morphology. This assessment can be conducted before, during, or after finasteride use to monitor changes. If fertility becomes a concern, a doctor may advise temporarily or permanently stopping finasteride. In such cases, semen parameters typically show improvement after the medication is discontinued. This decision should always be made in consultation with a healthcare professional.
Finasteride can pass into semen. While the risk is negligible for pregnant partners, some guidelines suggest men trying to conceive or whose partner is pregnant should consider discontinuing finasteride as a precautionary measure, under medical supervision. Beyond medication, male reproductive health is influenced by lifestyle factors like diet, regular physical activity, and avoiding smoking or excessive alcohol. Addressing these factors can complement medical management in supporting fertility.